Application Of Pulse Laser Deposition In Organic Perovskite Solar Cells

Recent years,organometal trihalide perovskite materials has become a hot spot in the research field of solar cells due to their advantages such as appropriate band gap,low exciton binding energy,high light absorption coefficient,high charge carrier mobility,long diffusion length and so on.This kind of solar cell has great potential in research and high value in applications,not only for its low cost but also its high photoelectric conversion efficiency.However,instability of organic perovskite materials seriously restrains their further developement in industry applications.This thesis devotes to the preparation of organic perovskite solar cells with large size grain in order to improve the stability and fabrication of ultrathin compact TiO₂ layer in perovskite solar cells as the electron transporting layer by pulsed laser deposition technology.The thesis is organized as below:In the first chapter,the related research background has been briefly introduced,including the development and working mechanisms of organic perovskite solar cells.In the second chapter,the background knowledge of our experiments,including the pulsed laser deposition technology,the technology used for preparation of other layers in organic perovskite solar cells,and main characterization methods have been briefly introduced.In the third chapter,we research the improvement of stability of the organic perovskite thin film.When meeting water,the organic perovskite material?CH₃NH₃PbI₃?will decompose which is very unstable in air.We fabricate CH₃NH₃PbI₃ thin films with large grain size in order to restrain damage of moisture in air to thin films by combination between pulsed laser deposition technology and vapour reaction process that effectively improves resistance of CH₃NH₃PbI₃ thin films to moisture.In the fourth chapter,we study the preparation of the ultrathin compact TiO₂ layer as the electron transporting layer in organic perovskite solar cells by pulsed laser deposition technology instead of spin coating.Organic perovskite solar cells with compact TiO₂ layers prepared by pulsed laser deposition technology can achieve the same performance of preparation by spin coating and this technology is beneficial for large-area preparation of compact TiO₂ layers compared with spin coating.In the fifth chapter,we summarize our present work and propose the future work.